Equinox path. ayanāṃśa: ayana "movement" + aṃśa"component"), also ayanabhāga (Sk. bhāga "portion"), is the Samskrtam term in Indian astronomy for the amount of precession, that is the difference between the Tropical (Sayana) and the Sidereal (Nirayana) longitudes. http://www.aryabhatt.com/astrology%20book/astrologyA4.htm "The ancient definition of ayanamsha was not called the precession of equinoxes but in measuring the length of the tropical year versus the sidereal year the ancients were essentially tracking the precession observable. Suryasiddhanta (iii, 9-10) defines ayanāṃśa: as the to and fro motion of the circle of asterisms (Nakshatra-chakra or Bhachakra) within a maximum range of + and - 27 degrees at an annual rate of 54" (versus the modern value of 50.3"). Burgess could not digest the idea of trepidating Nakshatra-chakra, and assumed that some error had crept in the text. On the basis of this assumption, he advocated the use of precession of equinoxes to define ayanamsha, following the arguments of his predecessors like Colebrooke. They assumed that ancient Indians did not know how to measure precession accurately and therefore invented a wrong concept of trepidating precession." http://en.wikipedia.org/wiki/Ayanamsa "...the first lunar mansion in Hindu astronomy was called "Aśvini", after the traditional names for Beta and Gamma Arietis, the Aśvins. Because the Hindu new year began with the vernal equinox, the Rig Veda contains over 50 new-year's related hymns to the twins, making them some of the most prominent characters in the work. Aries itself was known as "Aja" and "Meṣa".http://en.wikipedia.org/wiki/Aries_(constellation)
Have the Sayana-Nirayana siddhantas been resolved?